Reamer



June 16, 1931. Q BEARD 1,810,263

REAMER Filed Feb. 9, 1929 .35 ioperatingtool.

Patented Janelle, 193iY reir:

BEAMER Y applicati@ mearetruary 9, fi'aeg vseria1oNo'.-;3 3s,soe.

MyV invention relates to yexpansible reamers and'mo-re particularly to that class of reamers wherein the blades are integrally formed with the shank of the reamer.

The principal object of the invention is to secure maximum expansion of blades ywith minimum danger kof breakage.

Another object is to providev a reamer in which the blades will not become distorted ,or out of parallel when expanded, I accomplish the above-mentioned and other and inore specific objects by the improved conf struction'hereinafter described and claimed. Iny the accompanying drawings forming a part of this specification:

- Figure 1 isa side elevationof a reame'r.l embodying theV invention, as lemployed jto ream the piston pin bores of an internal combustion enginepiston, thevpiston-being shown 29 in outline; y i

Figure cis an enlarged fragmentary view of the rea-mer, `partly in sec-tion, showing the means kemployed in expanding the cutting` y blades, y l Y v' v 1 Figure 3 is a section taken on the line 3-3 ofFigure 2. i n' y Y Figure 4 is a detail of the self feeding member. f o i Referring more Aparticularly to the dra-wf 30. ings wherein theV same reference characters indicate like parts in all the iigures,'1`repre sents the reamerhaving the hollow shankiQ, the 'free end'of wbichis squared as at'to facilitate attachment of a wrench or other The outer open end of the y bore 4, of theshank 2,-is internally threaded as lat 5 for the purpose yof threadedly rece1ving the reduced threaded vportion 8 of a combined pilot and :expander 8,v the purpose of which will be explained hereinafter.

Cutting blades 6 are integrally formed onk the intermediate portion ofthe shank andr in order to impart :flexibilityto the blades, that is permit expansion yand contraction thereof,.by means of the pilot expander member-f8, elo-ngatedslots 7 are out -orotherwise formed.= These slots extend through and for asubstantial distancebeyond each end of that portion `of the shank onk which the cutting blades are formed and are inclined at a slight angle tothe axis ofthe/feather. The cutting blades arel similarly inclinedbut toa slightly greater degree than'the slots; As a further means of increasing resiliency or iexibility, the slotted portion of the shank adjacent the 4K55 cutting blades is given a spring temper, that is a softer or. lower temper'y than,y thevcut'tjing bladetemper. Y f

lTlien the cutting face of the blades 6 wear down, or kwhen it is desired to increaseV their ,60-

cutting capacity, the pilot expander member 8 'is'screwedhome inthe bore 4 until the beveledV end9 of the member 8 engages the shoulder 10, thus causin'glthe more iiexible or eX- pansible portions or areas adjacentthe blades 05 l to give".` A vmilled locknut- 11 locks the pilot g f expandermember inadjusted position.l -f

It will be `noted vfrom the foregoing thatv by providing *eiqaansible portions' adjacent eachend of theblades and'applyingthe eX- 'l0 panding force or pressure approximately midway the length ofthe blade portions, that the expansion of the lattenwillbe uniform, that is,lthe cutting surfaces. Will alwaysre main on an' even plane. Furthermore, as the i5.

blade portion of theshank,which isofY necessityk'h'ard and brittle,- is not'flexed duringL the expansion fofthecutters, aT greater range of expansiony 5 is obtained witho-ut .danger of bmalng .theiblades or 1 blade portionsy of. the 30 shank; L .l n y f j'npra'ctice tlie` enlarged threaded portion 8" ofthe pilotfeXpander member 8, together` withrthefreamer shank, is inserted through the pistonA pin bores 12 and 13 `of piston 14 in85 I the yorder named untilthe cuttingblades engage the bushing-15 to be reamed. A centeringsleeve 16 is then slipped over the enlarged threadedportion 8 of the pilot-eipandermember 8 and forced into the bush- 90 ing 17 .o

For the purpose of holding the guide sleeve 16 in .place and insuring a steady and uniform cutting action, a self feeding member 18 is v provided for attachment to the pilot-expander member 8. This feeding member comprises a preferably rectangular bar of metal having a substantially U-,shaped recess 19, cut in one edge thereof, the bottom of the recess f beingk semi-circular and threaded, as at 210 V19- in effect forming a. lead screw nut adapted to receive the threaded portion 8, of the pilot expander member 8. After the feed member 18 has been placed on the pilot-expander member and moved into engagement with the sleeve 16 to snugly yclamp the sleeve in the bore 13, the member 18 is held in place'by means of a latch member or plate 21 pivotallysecured to the member 18, adjacent the recess 19, by means of an adjusting thumb screwv22. Thedepth of the recess 19 is just suicient to receive the threaded pilot expander member and the threaded portion 20 of the recess 19 is sufcient in area to engage one half or slightly less than one half of the diameter` of the pilot-expander member thread. VVhen the* latch member or plate 21 is swung on its pivot to Figures 1 and 4 position, it will close the top of recess 19 and will barely engage the threaded reamer shank, thus holding the same securely to the threads 20 of the recess 19.

Continued turning of the reamer causes the cutting blades 6 to progressively enlarge thebore 12 of bushing 15 as the reamer is fed steadily forward by the feed member 18, rotation of thelatter being prevented by engagement of the free elongated end thereof with the vise or Work table, not shown, in which the piston is clamped, thus lea-ving the operators hands free to operate the device.

Having'thus described my invention What I claim is: Y i

A reamer comprising a hollow expansible shank, cutting blades formed on said shank,

a member having a reduced portion adapted for insertion Within said shank for expanding the same, said member having an enlarged threaded portion, a centering sleeve slidably mounted on said enlarged threaded portion and a threaded feeding member for engagement with the said enlarged threaded portion adapted to engage and hold the centering sleeve in place and to feed the reamer and bla des when said reamer is rotate In testimony whereof I a'lix my signature.

LAWRENCE O. BEARD. 

